diff mbox series

[3/3] vDPA/ifcvf: get_config_size should return dev specific config size

Message ID 20210414091832.5132-4-lingshan.zhu@intel.com (mailing list archive)
State New
Headers show
Series vDPA/ifcvf: enables Intel C5000X-PL virtio-blk | expand

Commit Message

Zhu, Lingshan April 14, 2021, 9:18 a.m. UTC
get_config_size() should return the size based on the decected
device type.

Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
---
 drivers/vdpa/ifcvf/ifcvf_main.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

Comments

Jason Wang April 15, 2021, 3:36 a.m. UTC | #1
在 2021/4/14 下午5:18, Zhu Lingshan 写道:
> get_config_size() should return the size based on the decected
> device type.
>
> Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>


Acked-by: Jason Wang <jasowang@redhat.com>


> ---
>   drivers/vdpa/ifcvf/ifcvf_main.c | 11 ++++++++++-
>   1 file changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/vdpa/ifcvf/ifcvf_main.c b/drivers/vdpa/ifcvf/ifcvf_main.c
> index 9b6a38b798fa..b48b9789b69e 100644
> --- a/drivers/vdpa/ifcvf/ifcvf_main.c
> +++ b/drivers/vdpa/ifcvf/ifcvf_main.c
> @@ -347,7 +347,16 @@ static u32 ifcvf_vdpa_get_vq_align(struct vdpa_device *vdpa_dev)
>   
>   static size_t ifcvf_vdpa_get_config_size(struct vdpa_device *vdpa_dev)
>   {
> -	return sizeof(struct virtio_net_config);
> +	struct ifcvf_hw *vf = vdpa_to_vf(vdpa_dev);
> +	size_t size;
> +
> +	if (vf->dev_type == VIRTIO_ID_NET)
> +		size = sizeof(struct virtio_net_config);
> +
> +	if (vf->dev_type == VIRTIO_ID_BLOCK)
> +		size = sizeof(struct virtio_blk_config);
> +
> +	return size;
>   }
>   
>   static void ifcvf_vdpa_get_config(struct vdpa_device *vdpa_dev,
Stefano Garzarella April 15, 2021, 8:12 a.m. UTC | #2
On Wed, Apr 14, 2021 at 05:18:32PM +0800, Zhu Lingshan wrote:
>get_config_size() should return the size based on the decected
>device type.
>
>Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
>---
> drivers/vdpa/ifcvf/ifcvf_main.c | 11 ++++++++++-
> 1 file changed, 10 insertions(+), 1 deletion(-)
>
>diff --git a/drivers/vdpa/ifcvf/ifcvf_main.c b/drivers/vdpa/ifcvf/ifcvf_main.c
>index 9b6a38b798fa..b48b9789b69e 100644
>--- a/drivers/vdpa/ifcvf/ifcvf_main.c
>+++ b/drivers/vdpa/ifcvf/ifcvf_main.c
>@@ -347,7 +347,16 @@ static u32 ifcvf_vdpa_get_vq_align(struct vdpa_device *vdpa_dev)
>
> static size_t ifcvf_vdpa_get_config_size(struct vdpa_device *vdpa_dev)
> {
>-	return sizeof(struct virtio_net_config);
>+	struct ifcvf_hw *vf = vdpa_to_vf(vdpa_dev);
>+	size_t size;
>+
>+	if (vf->dev_type == VIRTIO_ID_NET)
>+		size = sizeof(struct virtio_net_config);
>+
>+	if (vf->dev_type == VIRTIO_ID_BLOCK)
>+		size = sizeof(struct virtio_blk_config);
>+
>+	return size;

I'm not familiar with the ifcvf details, but can it happen that the 
device is not block or net?

Should we set `size` to 0 by default to handle this case or are we sure 
it's one of the two?

Maybe we should add a comment or a warning message in this case, to 
prevent some analysis tool or compiler from worrying that `size` might 
be uninitialized.

I was thinking something like this:

	switch(vf->dev_type) {
	case VIRTIO_ID_NET:
		size = sizeof(struct virtio_net_config);
		break;
	case VIRTIO_ID_BLOCK:
		size = sizeof(struct virtio_blk_config);
		break;
	default:
		/* or WARN(1, "") if dev_warn() not apply */
		dev_warn(... , "virtio ID [0x%x] not supported\n")
		size = 0;

	}

Thanks,
Stefano
Jason Wang April 15, 2021, 8:16 a.m. UTC | #3
在 2021/4/15 下午4:12, Stefano Garzarella 写道:
> On Wed, Apr 14, 2021 at 05:18:32PM +0800, Zhu Lingshan wrote:
>> get_config_size() should return the size based on the decected
>> device type.
>>
>> Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
>> ---
>> drivers/vdpa/ifcvf/ifcvf_main.c | 11 ++++++++++-
>> 1 file changed, 10 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/vdpa/ifcvf/ifcvf_main.c 
>> b/drivers/vdpa/ifcvf/ifcvf_main.c
>> index 9b6a38b798fa..b48b9789b69e 100644
>> --- a/drivers/vdpa/ifcvf/ifcvf_main.c
>> +++ b/drivers/vdpa/ifcvf/ifcvf_main.c
>> @@ -347,7 +347,16 @@ static u32 ifcvf_vdpa_get_vq_align(struct 
>> vdpa_device *vdpa_dev)
>>
>> static size_t ifcvf_vdpa_get_config_size(struct vdpa_device *vdpa_dev)
>> {
>> -    return sizeof(struct virtio_net_config);
>> +    struct ifcvf_hw *vf = vdpa_to_vf(vdpa_dev);
>> +    size_t size;
>> +
>> +    if (vf->dev_type == VIRTIO_ID_NET)
>> +        size = sizeof(struct virtio_net_config);
>> +
>> +    if (vf->dev_type == VIRTIO_ID_BLOCK)
>> +        size = sizeof(struct virtio_blk_config);
>> +
>> +    return size;
>
> I'm not familiar with the ifcvf details, but can it happen that the 
> device is not block or net?
>
> Should we set `size` to 0 by default to handle this case or are we 
> sure it's one of the two?
>
> Maybe we should add a comment or a warning message in this case, to 
> prevent some analysis tool or compiler from worrying that `size` might 
> be uninitialized.
>
> I was thinking something like this:
>
>     switch(vf->dev_type) {
>     case VIRTIO_ID_NET:
>         size = sizeof(struct virtio_net_config);
>         break;
>     case VIRTIO_ID_BLOCK:
>         size = sizeof(struct virtio_blk_config);
>         break;
>     default:
>         /* or WARN(1, "") if dev_warn() not apply */
>         dev_warn(... , "virtio ID [0x%x] not supported\n")
>         size = 0;
>
>     }
>

Yes, I agree.

Thanks


> Thanks,
> Stefano
>
diff mbox series

Patch

diff --git a/drivers/vdpa/ifcvf/ifcvf_main.c b/drivers/vdpa/ifcvf/ifcvf_main.c
index 9b6a38b798fa..b48b9789b69e 100644
--- a/drivers/vdpa/ifcvf/ifcvf_main.c
+++ b/drivers/vdpa/ifcvf/ifcvf_main.c
@@ -347,7 +347,16 @@  static u32 ifcvf_vdpa_get_vq_align(struct vdpa_device *vdpa_dev)
 
 static size_t ifcvf_vdpa_get_config_size(struct vdpa_device *vdpa_dev)
 {
-	return sizeof(struct virtio_net_config);
+	struct ifcvf_hw *vf = vdpa_to_vf(vdpa_dev);
+	size_t size;
+
+	if (vf->dev_type == VIRTIO_ID_NET)
+		size = sizeof(struct virtio_net_config);
+
+	if (vf->dev_type == VIRTIO_ID_BLOCK)
+		size = sizeof(struct virtio_blk_config);
+
+	return size;
 }
 
 static void ifcvf_vdpa_get_config(struct vdpa_device *vdpa_dev,